1 TAO Insert Specification 5_14_24 Revised.docx

NDBC STANDARD SPECIFICATION FOR FABRICATION OF HULL INSERTS USED IN THE TROPICAL ATMOSPHERE OCEAN (TAO) ARRAY

1.0 SCOPE

Fabrication of sixteen (16) TAO hull inserts.

1.1 General. This specification describes the requirements for the fabrication of hull inserts used in the Tropical Atmosphere Ocean (TAO) array. This requirement represents a single insert of which two are needed to be used together on a TAO buoy. The contractor shall provide all the necessary labor, material, equipment, facilities and services to fabricate and deliver the inserts to the National Data Buoy Center (NDBC).

1.2 Government Furnished Property. There will be no Government Furnished Equipment for this purchase order. The contractor shall provide the molds for the Hull Inserts along with any associated jigs used to maintain proper placement of the internal framework.

2.0 APPLICABLE DOCUMENTS

2.1 Government Documents. The following documents form a part of this specification to the extent referenced herein. Suffixes denoting the specific issue of each document are omitted from future references to the documents in this specification.

2.2 Industry Publications. The following documents of the issues specified form a part of this specification to the extent referenced herein. Suffixes denoting the specific issue of each document will be omitted from future references to the document in this specification.

2.4 Drawings. The following NDBC drawings form a part of this specification to the extent referenced herein and shall be referred to as "the drawings" throughout this specification:

3.0 REQUIREMENTS

3.1 General. The buoy shall be fiberglass over foam with Type 316 stainless steel framework and three attachment points.

3.2 Materials

3.2.1 Fiberglass. The fiberglass lay-up shall be layered with a combination of bulk fiberglass, applied by chopper gun, and 24 oz. roving. Equal bi-directional plus, minus, 45-degree strand material may be substituted for 24 oz. roving. Resin to glass ratio shall be 65 to 35. A smooth surface inside mold shall be used to form the fiberglass skin within which the bulk of the fiberglass shall be laid up. This shall be the required technique with the objective of producing inserts of consistent size and shape. Inserts with a surface finish consisting of dips or waves of greater than 1/4 inch may be rejected. All transitions must be fully feathered. Proper fiber glassing techniques shall be followed to prevent delamination.

3.2.2 Stainless Steel. All stainless steel components shall be ASTM A666 Type 316.

3.2.3 Floatation Foam. The floatation foam injected into the insert shall meet the requirement of MIL-P-21929B.

3.3 Construction

3.3.1 Fiberglass. The fiberglass shall have the following minimum thickness of 5/16” and a maximum thickness of 3/8”. Insert shall be constructed using alternate layers of chopped reinforcement, bi-directional and 24 oz. woven roving.

3.3.2 Procedure. Set the proper height of the frames to the inside of the shell. (the critical measurements here is the central location of the interior frame to the shell, height of the mounting holes above the shell and the alignment of the frame members relative to the notch in the shell). An additional 1/4-inch thickness of reinforcement must be applied to the upper and lower seams. Each 1/8 inch thickness band shall be approximately 5 inches wide consisting of chop, two layers of 1-1/2 oz. mat and two layers of unidirectional roving. This additional thickness must be feathered into the adjacent areas not in excess of 3 inches on top and bottom to provide a smooth transition. All voids shall be filled with Duraglass and covered with a gel coat with surface agent then sanded to fair and re-gel coated as required.

The entire finished surface of the buoy must be coated with gel coat with an air inhibited polyester surface. Apply an 18-inch wide strip of 40-mesh sand with gel coat to give a nonskid texture to the top of the insert.

Apply a smooth bead of 3M 5200 Marine adhesive/sealant to where the stainless steel framework and fiberglass meet.

The entire insert shall be colored with three coats of Ocean Gray Paint (FS Color 26173)

3.3.3 Welding. All stainless steel welding shall be in accordance with AWS Dl.6.

3.3.4 Flotation Foam Injection. The contractor shall have a procedure for injection and curing of the floatation foam that is in accordance with MIL-P-21929B and manufacturer's instructions.

4.0 QUALITY ASSURANCE

4.1 First Article

The contractor shall produce and deliver first article of one unit for inspection prior to commencing fabrication of the remaining units. The first article shall be delivered to NDBC within 5 months of receipt of award. The Government will complete inspection within 3 weeks of receipt of all first articles.

4.2 NDBC Production Inspection.

4.2.1 Visual Inspection. All units shall be visually inspected for quality of workmanship and conformance to the specifications and drawings.

5.0 DELIVERABLES

All deliverables shall be shipped to the following address by January 31, 2025:

National Data Buoy Center Attn: Property Officer Building 3203 Stennis Space Center, MS 39529 Email: anthony.baucum@noaa.gov Phone: 228-688-3460

Partial shipments are authorized at no additional cost to the Government.